Invertible evaporator



Filed July 18, 1957 INVENTOR JERZY MAKOWSKI i l H 15 ATTORNEYSINVERTIBLE EVAPORATOR N. Y., assignor to Fairchild Hagerstown, Md, a

Jerzy Makowski, Babylon,

Engine and Airplane Corporation, corporation of Maryland This inventionrelates to an apparatus in which vapor is evolved from a liquid andwhich is capable of operating in either an upright or an invertedposition.

In evaporative cooling systems, installed in aircraft, the cooler iscapable of functioning satisfactorily in an upright position, duringwhich the vapor formed by the evaporation of the coolant passes from theevaporator through a discharge passage at the top thereof. When,however, a cooler of this type is inverted, as sometimes happens when anairplane is maneuvering, the coolant is free to escape through thedischarge passage, with the result that a valuable supply of the coolantis lost. This not only imposes a weight penalty on the aircraft bynecessitating that it carry a greater reserve of coolant, but, even moreimportant, it may interrupt the operation of the cooler, causingoverheating of certain equipment, or necessitating its shutdown for atime.

The principal object of the present invention is to provide an apparatusfrom which vapor is readily withdrawn when operating in either anupright or an inverted position, but without substantial loss of theliquid.

In the invertible type vapor evolving apparatus of the presentinvention, a pair of relatively movable perforated plates is interposedbetween the upper level of the liquid and the vapor discharge passage.The perforations in one of the plates are laterally offset with respectto the perforations in the other of the plates, but in the uprightposition of the apparatus the plates are spaced apart so that the vaporis free to pass through the perforations in the plates in passing to thevapor discharge passage. When the apparatus is inverted, however, theplates come together and, due to the laterally offset perforations inthe two plates, the liquid is prevented from flowing, at

I least in substantial quantities, through the plates toward thedischarge passage.

The apparatus also includes an auxiliary passage which connects thelower portion of the apparatus with the vapor discharge passage. In theupright position of the apparatus, the entrance to this passage isblocked by the liquid coolant. In the inverted position, however, theauxiliary passage permits vapor which is evolved from the liquid coolantto be discharged through the vapor discharge passage.

Additional features of the present invention are concerned with themeans for supplying the liquid coolant to the apparatus in both theupright and inverted positions.

For a complete understanding of the present invention, reference may bemade to the detailed description which follows and to the accompanyingdrawings in which:

Figure 1 is an elevation view showing the invertible vapor evolvingapparatus of the present invention in cross-section; and

Figure 2 is a perspective view of the evaporator housing, with a portionthereof broken away.

Referring to the drawings, an evaporative cooler embodying the presentinvention is shown as comprising a United States Patent "ice housing 10containing a heat exchanger, generally designated 11, through which oneor more fluids can be circulated in out-of-contact heat exchangerelationship with a liquid coolant 12 which, for present purposes, willbe assumed to be water. In the type of evaporator cooler illustrated,the heat exchanger 11 is divided into two parts--one for cooling thecabin air and the other for cooling a lubricant. The cabin air isadmitted into the heat exchanger through an inlet conduit 13 anddischarged from the heat exchanger through a conduit 14. The lubricantis admitted into the heat exchanger through a conduit 15 and dischargedtherefrom through a conduit 16. It is, of course, understood that theair and lubricant are not intermingled with each other within the heatexchanger 11.

The liquid coolant or water is admitted into the housing 10 through aconduit 18 when the evaporator is in upright position, or through apassage 17 when the evaporator is in inverted position.

Steam or vapor evolved from the water or liquid coolant 12 passesupwardly through the housing 10 and is exhausted therefrom through avapor discharge vent 20 in the upper portion ofthe housing. Twoperforated baflie plates 21 and 22 are accommodated in the upper regionof the housing 10 intermediate the liquid level of the coolant 12 andthe entrance to the discharge vent 20. The perforations 21a in the upperbaffle plate 21 are staggered or offset in relation to the perforations22a in the lower baffle plate 22. The upper bafiie plate is fixedlymounted to the walls forming the interior of the housing, and the lowerbaflie plate 22 is movable relatively thereto. When the housing is inupright position, the lower perforated plate 22 is supported on a ledge23 which projects inwardly from the walls forming the interior of thehousing. When the perforated bafiie plate 22 is supported on the ledge23, the baffle plates 21 and 22 are spaced apart, so that,notwithstanding the fact that the perforations in each are staggered oroffset laterally in relation to each other, the vapor evolved from theliquid coolant 12 is free to pass through the perforations to thedischarge vent 20. However, when the housing 10 is inverted, theperforated plate 22 falls by gravity against the upper perforated plate21, bringing the plates into face-to-face contact, and when this takesplace the perforations in each bafiie plate are closed by the otherplate. As a consequence, the liquid coolant will be prevented fromflowing, at least in substantial quantities, from the housing throughthe discharge vent 20.

The effectiveness of the seal may be increased by various means such asby afiixing flexible gaskets to the adjacent sides of the baffle platesaround each of the perforations therein.

When the housing 10 is in inverted position, the vapor evolved from theliquid coolant is still free to be withdrawn from the housing 10 throughthe discharge vent 20 by flowing through an auxiliary passage within aconduit 24. The lower end of the conduit 24 communicates with the lowerportion of the housing 10, and the upper end thereof communicates withthe vent 20. When the housing is in upright position, as shown in thedrawings, the liquid level of the coolant is at a level higher than theentrance to the conduit 24, so that the entrance is closed to vaporevolved from the surface of the liquid coolant.

To prevent unnecessary ltms of the liquid, a filter or gauze layer 25may be accommodated within the housing above the 'baffle plate 21. Inaddition, a baflle plate '26 may be placed at the entrance end of thedischarge vent 20. The gauze layer 25 and the baffle plate 26 preventmoisture particles 01' drops from being discharged with the vaporthrough the vent 20, thereby preventing unnecessary dissipation of theliquid coolant. The gauze layer"25 also absorbs moisture which seepsthrough the perforated -baflie plates 21' and 22 when the housing isinverted. The vapor, .however, is free to pass readily through the gauzelaye'r'25.

In the upright position of the housing 10, the liquid coolant isadmitted thereto through a conduit30, a. float valve 31 accommodatedwithin a chamber 32, and the conduit 18 which. connects the interior ofthe chamber 32 with the interior of thehousing. Thefloat valve31comprises a float 31a connected to one end of a lever 31b pivoted at31c,- and a valve head 31d connected to the lever31b on the oppositeside'of the pivot. 'The' chamber 32 is supported beside the'housing ata'heightwhich is determined by the-level at 'which it is'desired tomaintain the liquid within the'housing ltl. The weight of the float 31awill lift the valvehead-31d-to open-position, thereby admitting liquidinto the'housing through the conduit through theconduit 17. .In theupright position of the housing, gravity maintains the :weighted valve36 closed, so that the level of the liquid withinthe housing isregulated by..the float valve 31., :However,:, inthe inverted position.of the housing, the valve. 36-.opens and permits the flowof liquid intothe housing 10 at a rate which is determinedby the calibrated orifice37. The longitudinal movement of the valve 36 within the chamber 35 isguided by a group of parallel members 39 surrounding the valve.

A connection 38 between the conduit17-on the downstream side of theorifice 37 and the chamber 32 permits the liquid entrappedwithinthechamher 32 to flow into the housing when the housing is.inverted. However, as soon as this entrappedliquid is'withdrawn fromthe chamber, the weight of .the float 31a. willholdthe valve head 31dclosed. Since it is not .expected that the cooler will be operating ininverted position for a substantial period of time, it is not likely.that a sufiicient quantity of the liquid will be admitted into thehousing 10 via the conduit 17 such that the level of the liquid thereinwould be raised high enough tolift the float 31a and thereby open thevalve 31d.' This, however, can be prevented even in the event ofprolonged operation in the inverted position by limiting the size of therestricted orifice 37.

The invention has been shown in preferred form and by way of exampleonly, and obviously many variations and modifications may be madetherein withoutdeparting from the spirit of the invention. Theinvention, therefore, is not to be limited to any specified form orembodiment, except in so far as such limitations are set forth in theclaims.

I claim:

1. An apparatus in whichvapor is evolved from a liquid comprising ahousing for the liquid, a vapor discharge passage, and a pair ofrelatively movable perforated plates separating the liquid in thehousing and the vapor discharge passage, each perforation in one of theplates being offset with respect to each perforation in the other of theplates, said perforated plates being spaced apart in one position of theevaporator to permit the evolved vapor to pass through both of saidperforated plates and to be discharged from the housing through thevapor discharge passage, and said perforated plates being movabletogether when the evaporator is inverted to stop the flow of the liquidthrough said perforated plates.

2. An apparatus as set forth in claim 1 including means forming anauxiliary passage between the vapor discharge passage and the interiorof the housing on the opposite side of the perforated plates, saidauxiliary passage permitting-vapor to be discharged from the housingwhen the housing is inverted, the entrance to the auxiliary passagebeing below the usual-level ofthe vapor evolving liquid when the housingis inupright position, thereby preventing the flow of vapor throughsaidauxiliary passage in the upright position of the housing.

.3. Anapparatus as set forth in claim 1; including a .passageforadmitting liquidinto the housing in .the upright. position of l thehousing, a passageforadmitting liquid into the housing in the invertedposition'of the housing, means. for closing lone. passage in the.upright position of. the housing, and means for closing the otherpassage in the inverted position of .the housing.

4. An apparatus as set forth;in claim 1. including means for maintainingapredeterminedlevelof the liquid .in the housing 'whenthe housing isin:one position and means for feeding aregulated quantity, of. theliquid to the housing whenqthe housing is. in inverted position.

5. An invertible apparatus inwhich' vapor is evolved from a liquidcomprising a housing for the; liquid, a discharge passage communicatingwith the upper region of the housing when the housing is. in uprightposition, a pair of perforatedplates accommodated in the housingseparating the liquid and the discharge passage, the perforations in oneplate being offset laterally in relation to the perforations inthe other'plate, and means for supporting the lower of the plates spacially 1separated from the upper plate in the upright position of the housing,permitting the vapor evolved from the liquid to pass through theperforations of both plates to, thedischarge passage, said lower. platefalling by gravity into contact with the upper plate when the housing isinverted to stop theflow of the liquid throughsaid perforated plates.

6. An invertible apparatus as set forth in, claim 5 including meansforming an auxiliary passage, the upper end of which communicates with.the region above the perforated plates and the lower. end of. whichcommunicates with the region below the perforated plates and below theusual level of the liquid in the housing, said auxiliary passagepermittingthe vapor to be. removed from the housing. when the,housing isinverted.

No references cited.

